In order to remove heavy metal ions from aqueous solutions, precipitation, ion exchange, reverse osmosis are extensively used in the prior art. And in order to remove organic compounds, aeration has been used for over a half century. However, this method only allows removal of volatile organic compounds. Organic contaminants are decomposed into products more perishable in nature by chemical oxidation performed using ozone, permanganate and chlorine and by photooxidation performed using UV/H2O2 or UV/TiO2. However, these methods require further processing, which results in an increase in cost; and also, toxic products that may be generated from decomposition causes secondary contamination.
A majority of the organic contaminants are toxic and resistant to aerobic digestion. Therefore, organic contaminants hinder bacterial growth in biological purification methods, thereby reducing efficiency of the method. The most common devices used in obtaining potable water are those operating based on reverse osmosis principle. Although this method is reliable and effective, its capacity is low and the membrane used therein is costly and due to its working principle, it produces more waste water than clean water, as a result of which the cost of the obtained water is high. Furthermore, devices that are produced using silica sand or micro filters are able to remove only solid particles of certain size, and more importantly, dissolved compounds such as pesticides cannot be removed.
Adsorption using mainly activated carbons as adsorbent is a more advantageous and the most frequently used method in the available devices, since it does not require complex and costly systems as compared to other methods, and particularly, chemically and biologically stable compounds may be removed by adsorption to a certain extent. On the other hand, regeneration of adsorbent is limited, the contaminants may only be removed to a certain extent and the capacity is low, which leads to an increase in the cost. Furthermore, adsorption typically takes a long time and due to microbiologic growth on the adsorbent, there is a smell problem with the water obtained.
Problems in relation with the household and pool water are listed below:                1. Organic chemicals        2. Microorganisms        3. Inorganic ions        4. pH        
Technically important parameters in solving these problems are as follows:                a) Removal rate        b) Efficiency        c) Capacity        d) Economic        
Among the current applications, reverse osmosis addresses the first 4 problems, but it is disadvantageous for the parameter d. Moreover, since it removes all ions in water, it causes secondary health problems resulting from mineral deficiency. The ion exchange method solves only the 3rd problem. Although adsorption provides a partial solution for the 1st, 2nd and 3rd problems and is suitable for the parameter d, it is disadvantageous for the parameters a, b and c.